1 files changed, 22 insertions, 0 deletions
diff --git a/rtl/src/immediate_extend.v b/rtl/src/immediate_extend.v
new file mode 100644
index 0000000..14a9a33
--- /dev/null
+++ b/rtl/src/immediate_extend.v
@@ -0,0 +1,22 @@
+module immediate_extend (
+  input [31:0] instr,
+  input [2:0] imm_src,
+  
+  output reg [31:0] imm
+);
+
+`include "include/consts.vh"
+
+always @ (*) begin
+  case (imm_src)
+    INSTR_FORMAT_I:  imm = { {21{instr[31]}}, instr[30:20] };                                // I
+    INSTR_FORMAT_S:  imm = { {21{instr[31]}}, instr[30:25], instr[11:7] };                   // S
+    INSTR_FORMAT_B:  imm = { {20{instr[31]}}, instr[7], instr[30:25], instr[11:8], 1'b0 };   // B
+    INSTR_FORMAT_U:  imm = { instr[31:12], 12'b0 };                                          // U
+    INSTR_FORMAT_J:  imm = { {12{instr[31]}}, instr[19:12], instr[20], instr[30:21], 1'b0 }; // J
+    default:         imm = 32'b0;                                                            // Unknown
+  endcase
+end
+
+
+endmodule